Silicon anisotropic etching in alkaline solutions II on the influence of anisotropy on the smoothness of etched surfaces

Experiments were carried out with anisotropic etching of Si(100) in alkaline solutions from the point of view of surface quality. The circumstances needed to obtain surfaces of various level of smoothness were established. The problem why etched surface is of mirror-like quality, texturized, i.e., covered on the whole with random inequality (sometime of pyramids shape) as well ones covered with single separated hillocks is discussed in the term of anisotropy. Some analogies between random texturizing, obtaining the hillocks and etching through a patterned SiO₂ mask were stated.